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author | Jeff Liu <jeff.liu@oracle.com> | 2013-01-28 21:25:35 +0800 |
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committer | Ben Myers <bpm@sgi.com> | 2013-02-01 14:35:06 -0600 |
commit | 4f3b57832ba39223c6f8823d07b9fb206e282ced (patch) | |
tree | 071d5d58fee6d361e4197804c37f8ffced556812 /fs | |
parent | 2729423cf2ef3ac51d040f24a5ddd84c1b2acc70 (diff) | |
download | linux-stable-4f3b57832ba39223c6f8823d07b9fb206e282ced.tar.gz linux-stable-4f3b57832ba39223c6f8823d07b9fb206e282ced.tar.bz2 linux-stable-4f3b57832ba39223c6f8823d07b9fb206e282ced.zip |
xfs: add a helper to figure out the space log reservation per item
Add a new helper xfs_calc_buf_res() to calcuate out the transaction space
reservations per item. xfs_buf_log_overhead() is used to figure out the
extra space for struct xfs_buf_log_format that gets written into the log
for every buffer as well as a log opheader, i.e. struct xlog_op_header.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/xfs/xfs_trans.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 06ed520a767f..6c601ea77a9e 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -37,14 +37,45 @@ #include "xfs_extent_busy.h" #include "xfs_bmap.h" #include "xfs_quota.h" +#include "xfs_qm.h" #include "xfs_trans_priv.h" #include "xfs_trans_space.h" #include "xfs_inode_item.h" +#include "xfs_log_priv.h" +#include "xfs_buf_item.h" #include "xfs_trace.h" kmem_zone_t *xfs_trans_zone; kmem_zone_t *xfs_log_item_desc_zone; +/* + * A buffer has a format structure overhead in the log in addition + * to the data, so we need to take this into account when reserving + * space in a transaction for a buffer. Round the space required up + * to a multiple of 128 bytes so that we don't change the historical + * reservation that has been used for this overhead. + */ +STATIC uint +xfs_buf_log_overhead(void) +{ + return round_up(sizeof(struct xlog_op_header) + + sizeof(struct xfs_buf_log_format), 128); +} + +/* + * Calculate out transaction log reservation per item in bytes. + * + * The nbufs argument is used to indicate the number of items that + * will be changed in a transaction. size is used to tell how many + * bytes should be reserved per item. + */ +STATIC uint +xfs_calc_buf_res( + uint nbufs, + uint size) +{ + return nbufs * (size + xfs_buf_log_overhead()); +} /* * Various log reservation values. |